DE19940348C5 - Two-piece endoprosthesis, especially for an artificial hip joint - Google Patents

Abstract

endoprosthesis especially for an artificial one Hip joint, consisting of a shaft (1) for implantation, for example into a proximal femur bone (11), and from one, to a first End portion (8), in particular a femoral head (9) bearing neck (2), the neck (2) having a second end portion (17) in one Recording (4) of the shank (1) in the press fit or the like inserted is, the first end portion (8) opposite the second end portion (17) is angled and the second end portion (17) with its central longitudinal axis (14) a longitudinal axis (18) of the shaft (1) and the central longitudinal axis (14) to the femoral head (9) indicative head area (20) of the first end portion (8), characterized that the neck (2) in the region of the second end portion (17) a Cross-sectional profile in the manner of a splined cone (16) and the recording (4) a cross-sectional profile corresponding to the splined cone (16) having the neck (2) in the inserted position in a Plurality of defined angular positions with respect to the shaft (1) at this can be fixed non-rotatably, ...

Description

The The invention relates to an endoprosthesis according to the preamble of the claim 1.

Such endoprosthesis is already from the DE 36 00 804 C1 known.

In advanced wear and tear of the hip joint, the coxathrosis, the joint function of femoral head and socket is irreparably disturbed, so that these parts must be replaced by artificial parts. A hip joint exists, as in the 5 is reproduced as a known prior art, from a femoral head 9 in an artificial socket 10 is mounted rotatably or pivotally. The femoral head 9 is on a neck 2 held a two-piece endoprosthesis, the neck 2 in the area of the second end section into a receptacle 4 on the shaft 1 the prosthesis is inserted. The shaft 1 is used with bone cement in the femur 11 anchored. Likewise, the artificial joint socket 10 with bone cement 12 in the bony pan 13 anchored.

Such, for example from the US 5,135,529 A known two-piece endoprosthesis allows to adjust by means of an individual positioning of the particular angled neck relative to the shaft, the inclination angle of the femoral head-bearing end portion of the neck with respect to the longitudinal axis of the shaft.

Farther It is already known the connection between the neck and the Shank by a cross-sectionally elliptical Preßkonus produce. However, in this known embodiment is a individual adjustment options or positioning the neck with respect to the shaft only limited possible. To have to Necks with different inclinations are kept ready, resulting in one very high stocking and costs leads.

In contrast, lies The invention is based on the object, an endoprosthesis with the aforementioned Further develop features to allow the physician to intraoperatively the rotation angle and / or the throat projection in length and / or Tendency for surgical correction of dysplastic hips optimize, with the neck in relation the shaft in different positions adjustable and safe should be detectable.

These The object is achieved by a Endoprosthesis with the features of claim 1 solved. advantageous Embodiments are the subject of dependent claims.

By the invention is achieved that also in a rotation of the neck at any angle, so for example even at an angle of 180 °, the ball head in any desired Position can be placed in the socket. The surgeon is thus able to malposition of the leg, in which the endoprosthesis implanted, to correct interoperatively step by step. there it is envisaged that the Neck in the region of the second end portion a cross-sectional profile in the manner of a splined cone and the inclusion of a splined cone having corresponding cross-sectional profile, wherein the neck in the inserted position in a plurality of defined angular positions in terms of the shaft is fixed to this non-rotatably. Through this Measure becomes a press fit between the shaft and the neck by means of a positive profiling created so that the Neck in different positions or solid angles across from the shaft is adjustable and secure. So, for example the solid angle between the first end portion of the neck and the Shank in the range of about 0 to 90 °, for example, set in extreme cases become. Another advantage is that the area between the second end portion of the neck and the receptacle of the shaft by the formation of a positive profiling in total is enlarged, so that also the holding or clamping force increased overall. The endoprosthesis is, in The shape of a multi - parted cone, with a cone that locks in a jumbled manner or formed with a multi-wedged cone adaptation for implantation optimization. The possibilities This endoprosthesis exist inter alia in a surgical Correction for dysplastic hips (Varus or valgus correction, individual step-by-step graduation the retro or antetorision). Also, the surgeon is interoperative capable of both the throat and the retro / anti-torsion angle step for Step to optimize. Also, the Vielkeilkonus by over the Circumference of the neck or the receptacle distributed depressions and / or increases educated.

Thereby, that the Depressions and / or elevations essentially in the longitudinal direction the neck or the recording is a simple one Inserting the second end portion of the neck into the receptacle ensures the shaft.

In this case, it is also possible to attach the splined cone only to partial regions in the longitudinal direction along a central longitudinal axis of the neck. Of course, the same applies to the cross-sectional profile mounted in the side wall of the receptacle of the shaft. Likewise, the splined cone does not have to extend over the entire circumference of the neck or inner circumference of the receptacle. So it may, for example, be sufficient to provide only a few sectors of the circumference with a corresponding spline cone. It is understood that the invention can also be modified such that the shaft has a pin with mounted on the outer wall Vielkeilkonus and the neck is provided with a correspondingly profiled receptacle for the pin.

Especially can these depressions and / or elevation be formed meander- or wave-like.

To another embodiment the invention, the cross-sectional profile in the manner of a rosette be formed.

From Advantage of the splined cone is between about six to eighteen, preferably eight to twelve Depressions and / or elevations.

To another turn advantageous embodiment of the invention It makes sense that the Neck of the two-piece endoprosthesis with different neck lengths respectively Neck discharges is provided. While the necks according to the prior art not only in different lengths, but also with respect to the angle or solid angle different bends should be kept is it at the neck of the two-part endoprosthesis according to the invention only necessary to provide different neck lengths or neck discharges, which significantly reduces warehousing and costs.

Further Advantages and applications The present invention will become apparent from the following description an embodiment based on the drawings.

It demonstrate:

1 a cross-section through an embodiment of the two-part endoprosthesis according to the invention with shaft and neck inserted, wherein the free end of the neck is for receiving a femoral head,

2 the two-piece endoprosthesis of 1 , but rotated by 90 °,

3 a perspective view of an embodiment of the shaft of the endoprosthesis according to the invention,

4 in a schematic representation of the inserted into the receptacle of the shaft second end portion of the neck and

5 the construction of an artificial hip joint after the. State of the art in a schematic representation.

The in the 1 to 4 illustrated embodiment of the invention two-part endoprosthesis consists of a shaft 1 For example, for implantation in a proximal femur bone, and from a neck 2 which is at a first end section 8th for example, a femoral head 9 ( 5 ) wearing. The neck 2 is with a second end portion 17 in a recording 4 of the shaft 1 in a press fit or the like plugged.

In the area of the second end section 17 owns the neck 2 a cross-sectional profile in the manner of a splined profile 16 , Also the recording 4 of the shaft 1 is in the side wall with a corresponding cross-sectional profile, such as a splined cone 16 , fitted. Because of this measure is the neck 2 in the inserted position in a plurality of defined angular positions relative to the shaft 1 Non-rotatably attached to this.

The neck 2 is in the range of the second end section 17 , in particular designed as a splined shaft, splined cone or the like. Not shown in the drawing is the variant that the Vielkeilkonus 16 only on partial areas in the longitudinal direction along a central longitudinal axis 14 of the neck 2 is appropriate.

As in particular the 3 and 4 can be taken, is the Vielkeilkonus 16 through the circumference of the neck 2 or the recording 4 distributed wells 3 . 5 and / or increases 6 . 7 educated. The wells 3 . 5 respectively 6 . 7 are meandering or wave-like. Also, the cross-sectional profile may be formed in the manner of a rosette. The wells 3 . 5 and / or increases 6 . 7 extend substantially in the longitudinal direction of the neck 2 or the recording 4 , The Vielkeilkonus 16 points between about 6 and 18 , prefers 8th to 12 wells 3 . 5 and / or increases 6 . 7 on.

How the particular 1 . 3 show, owns the neck 2 an angling 15 of preferably about 10 ° to 20 °, in particular about 15 ° or is the first end portion 8th opposite the second end portion 17 angled by an angle 160 ° ≤ γ ≤ 170 °, in particular γ ≈ 165 °. The bend is approximately in the middle of the neck 2 arranged.

Preference is given to several necks 2 provided with different neck lengths or Halsausladungen, according to the individual requirements in the recording 4 of the shaft 1 are pluggable.

By individually positioning the neck 2 in relation to the shaft 1 can be different solid angle of the femoral head 9 carrying first end portion 8th with respect to the central longitudinal axis 14 of the neck 2 and with respect to the longitudinal axis 18 of the shaft 1 realize. Due to the special profiling of the neck 2 in the region of the second end portion 17 arise defined and fixed in their angular position adjustment of the neck 2 relative to the shaft 1 ,

Depending on the individual requirements can have several necks 2 are available, which have a different neck length or neck discharge. However, all available necks are non-rotatable by means of the particular cross-sectional profile in one of several defined angular positions on the shaft 1 set rotatable in the inserted position. This screening between the cross-sectional profile of the neck 2 and the cross-sectional profile of the receptacle 4 of the shaft 1 allows a defined setting of the neck in the predetermined by the detent steps. For example, distributed over the circumference twelve or more and fewer detents may be provided. This makes it possible that the solid angle between the first end portion 8th of the neck 2 can be set in the range of 0 to extreme, for example, 90 °. Also, the abutment surface between the second end portion 17 of the neck 2 and the side wall of the receptacle 4 of the shaft 1 increased by the formation of a positive profiling, so that the holding force of the press fit is increased overall.

in the Frame is self-evident also possible, Necks with different length, Discharge, bend, grid, diameter or the like use.

Also the individual shaping of the second end section 17 of the neck can be variable, for example, this second end portion 17 be formed as a cylindrical or conical body, in which case the shape of the recording 4 adapted accordingly. LIST OF REFERENCE NUMBERS

1

shaft

2

neck

3

deepening on the cone

4

admission

5

deepening on the shaft

6

Increase on spigot

7

Increase on shaft

8th

first end

9

Femoral Head

 10

artificial socket

11

thighbone

12

bone cement

13

bony pan

14

Central longitudinal axis

15

angling

16

Splined cone

17

second end

18

longitudinal axis

20

head face

Claims (8)

Endoprosthesis, in particular for an artificial hip joint, consisting of a shaft ( 1 ) for implantation, for example in a proximal femur bone ( 11 ), and from one, at a first end portion ( 8th ), in particular a femoral head ( 9 ) wearing neck ( 2 ), whereby the neck ( 2 ) with a second end portion ( 17 ) in a recording ( 4 ) of the shaft ( 1 ) in the press fit or the like can be inserted, the first end portion ( 8th ) in relation to the second end section ( 17 ) is angled and the second end portion ( 17 ) with its central longitudinal axis ( 14 ) a longitudinal axis ( 18 ) of the shaft ( 1 ) and the central longitudinal axis ( 14 ) one to the femoral head ( 9 ) indicative head surface ( 20 ) of the first end section ( 8th ), characterized in that the neck ( 2 ) in the region of the second end portion ( 17 ) a cross-sectional profile in the manner of a splined cone ( 16 ) and the recording ( 4 ) to the splined cone ( 16 ) have corresponding cross-sectional profile, wherein the neck ( 2 ) in the inserted position in a plurality of defined angular positions with respect to the shaft ( 1 ) is fixed to this non-rotatably, the Vielkeilkonus ( 16 ) by its circumference or its reception ( 4 ) distributed wells ( 3 . 5 ) and / or increases ( 6 . 7 ) is formed and the depressions ( 3 . 5 ) and / or increases ( 6 . 7 ) substantially in the longitudinal direction of the neck ( 2 ) or recording ( 4 ), and that at the Vielkeilkonus of the neck ( 2 ) in the direction of the first end portion ( 8th ) extending cylindrical portion connects with a shape adapted thereto portion of the receptacle ( 4 ) towards the proximal shaft end. Endoprosthesis according to claim 1, characterized in that the first end portion ( 8th ) with the second end portion ( 17 ) forms an angle of 160 ° ≤ γ ≤ 170 °, in particular γ about 165 °. Endoprosthesis according to Claim 2, characterized in that the end sections forming the angle γ ( 8th . 17 ) are approximately the same length. Endoprosthesis according to one of claims 1 or 3, characterized in that the splined cone ( 16 ) on partial areas in the longitudinal direction ent long of a central longitudinal axis ( 14 ) of the neck ( 2 ) is attached. Endoprosthesis according to one of claims 1 to 4, characterized in that the depressions ( 3 . 5 ) and / or increases ( 6 . 7 ) meander- or wave-like are formed. Endoprosthesis according to one of claims 1 to 5, characterized that this Cross-sectional profile is designed in the manner of a rosette. Endoprosthesis according to one of claims 1 to 6, characterized in that the splined cone ( 16 ) between about six to eighteen, preferably eight to twelve wells ( 3 . 5 ) and / or increases ( 6 . 7 ) having. Endoprosthesis according to one of the preceding claims, characterized in that the neck ( 2 ) is provided with different neck lengths or Halsausladungen.